Welcome to the forum
Nichodeamus,
ADDENDUM: If your accounts are using IMAP with IDLE/Push enabled then please scroll down to the post by Jeff that describes in detail the one exception regarding "forced" Mail Checks in which case either an account right-click Mail Check (Point #5 below in my post) or an account disconnect would be required to perform a "forced" Mail Check (but then "forced" Mail Checks for accounts using these protocols isn't necessary anyway
).
To clarify, if you have the POP Peeper interface open and force an on demand "Mail Check" do you not see any status messages of any kind in the "Status line" at the bottom of the POP Peeper interface (just below POP Peepers right inbox pane) such as "logging in" or "connecting..." or "retrieving inbox..." or "retrieving mail..." or "retrieving number of messages" etc. etc.? And if not then what you are saying is all that you do see is nothing more than the "XX Minute(s) remaining until next mail check" status getting reset to the (starting) "Polling interval" value?
I ask the question because I am unable to duplicate this issue (testing this multiple times).
Please follow-up with a reply to all of the requests/questions below:
1.) What type of accounts do you have (i.e. Yahoo, Gmail, Outlook.com etc.)?
2.) What type of protocol(s) are you using (Server type = i.e. IMAP, POP3, Yahoo, Gmail, Hotmail/Outlook etc.)?
3.) If you right-click on an account and select "Server info" what is it that you see for "Last success:...." for that account? ---- which should display the last date/time of the last Mail Check.
4.) Are you getting any account errors? (note: "last error:..." is also displayed under the "Last success:..." in the "Server info" display box).
5.) What happens if you right-click on a specific account and select "Check mail" from the context menu? (Do you see any activity at all in the "Status bar" at the bottom of the open POP Peeper interface?).
6.) Have you tried sending a "test" message to a specific account and then doing a "Mail check" for that specific account that the message was sent to i.e. a right-click on that specific account and selecting "Mail check" to see if the message you sent is retrieved by POP Peeper? (if not please try this test and post your results)
7.) It is also important to from the main POP Peeper menu click on "File" > "Error overview" (regardless if you have any errors or not --
it may be a blank box) and then click on the "Copy" button in that "Error overview" window and then "Paste" (right-click and select "Paste") to this topic the copied information (there will be information copied whether you have [displayed] errors or not --- which will provide us with additional POP Peeper data that applies to you specifically that can be helpful to us in analyzing this issue).
8.) If you are using either of the "IMAP" and/or "POP3" protocol(s) on your account(s) then please go to "Tools" > "Options" > "Message retrieval" and post what the value is that you have for the "POP3/IMAP message limit" option.
9.) In "Tools" > "Options" > "Connection"; what "Connection type" are you using?
10.) And lastly, when did this issue start and as of the time it started have you changed anything involving the computers security software i.e. Firewall and/or AV protection etc.?
11.) On and one more thing, if you have made changes of any kind (added software or made setting changes) related to point #10 above --- then have you since that time tried rebooting your system?
That's about all I can think of for now that may be of some help.
Thanks!